1. Field of the Invention
This invention generally relates to synthetic soil and, more particularly to a blend of materials which can be used as a plant-growth medium, as a cover material for solid waste landfills or disturbed soil areas, and as a medium for treating contaminated water.
2. Background Art
Currently, solid waste disposal sites are typically covered with clay or another impermeable membrane such as strong plastic to keep rain water from infiltrating the waste and leaching out into the ground water. Such coverings are very expensive to install and maintain. The desirability of using synthetic soil materials in covering closed landfills and reclamation of disturbed soil areas such as mined, filled, and regraded land has recently been recognized. An article in the Post-Standard newspaper on Apr. 19, 1991 reported on a student proposal "to use processed bottom ash from an incinerator and some form of compost in a 1-to-30 ratio" (subsequently corrected to 1-to-3 ratio) as a waste bed cover.
Compost, for a long time has been used as a soil enriching material. Compost contains the nutrients used in relatively large quantities for plant growth. The earlier proposed waste bed cover accordingly employed compost as the primary ingredient.
Landfills and the disturbed soil areas often cover many acres and thus would require vast quantities of compost to implement the earlier proposal. Unfortunately, compost is not as readily available as municipal solid waste incinerator ash which today is produced in many locations and is typically disposed of in landfills.
Accordingly, a need still persists for a readily available and economically feasible alternative to the use of impermeable membranes in covering and vegetating solid waste landfills.